All about cookie syncing

Important: Please ensure your CMP configuration includes new Vendor ID 1469 for 1st Party data tracking. Additionally, include Vendor ID 301 if cookie sync is enabled. Learn more

Since cookies are domain-specific, browsers do not send cookies from other domains with server requests. To establish a common user identifier across platforms, a translation mechanism known as cookie syncing is required. Zeotap CDP allows you to collect user web data from different platforms and target users by syncing cookies with selected partners.

Cookie syncing is pre-configured per source write key.
Channel cookies are mapped to the Zeotap cookie and any user identifiers you send.
Syncs are fired as image pixels or iframe tags.
Web image pixels can sync with only one partner per call; the highest-priority partner is selected.
To control cookie syncing consent per individual channel partner, configure partnerConsentKeyMap during init.

By default, the cookie sync will render all partners’ cookies. To restrict, please reach out to your Zeotap representative or Zeotap Support. Reach out to your Customer Success Manager (CSM) for activation or partner configuration.

How Zeotap CDP Uses Cookies

Cookies are a preferred method for maintaining a browser-based user identifier (known or anonymous). These identifiers are associated with all inbound events captured by the Zeotap JavaScript tag. The following table lists all cookies set or read by the Zeotap SDK, including their purpose, scope, and lifecycle.

Cookie	Cookie Type	Name (as per Cookie Storage)	Read / Write	Purpose	Value	Default Expiry	Set When	Cleared When
ZI	First-party	`zpstorage_{{Base64.encode(API_KEY)}}zi`	Read / Write	Client ID used to recognise a user by device, browser, or domain-generated options	Random UUID	365 days 7 days (Safari)	On consent set with `consent.track = true` `setZI()` `resetZI()`	On consent set with `consent.track = false`
Identity	First-party	`zpstorage_{{Base64.encode(API_KEY)}}identity`	Read / Write	Stores user identities such as hashed email, cell number, login ID, and unhashed `fpuid`	Base64-encoded JSON	365 days 7 days (Safari)	On consent set (empty) On options change (empty) `setUserIdentities()`	On consent set with `consent.track = false`
ZS	First-party	`zpstorage_{{Base64.encode(API_KEY)}}zs`	Read / Write	Session ID unique per device, browser, domain, or session	Random UUID	60 minutes 7 days (Safari)	On consent set with `consent.track = true`	On consent set with `consent.track = false`
GDPR Consent	First-party	`euconsent-v2`	Read	Stores GDPR consent string set by TCF-compliant CMP	Encoded consent string	7 days (Safari)	When user interacts with CMP	—
GA Client ID	First-party	`{{cookie prefix as per SDK Configurations}}_ga`	Read	Reads Google Analytics Client ID	GA cookie value	7 days (Safari)	—	—
GA User ID	First-party	`{{cookie name as per SDK Configurations}}`	Read	Reads GA User ID for POST calls (all or post-login only)	GA cookie value	7 days (Safari)	—	—
IDP	First-party	`IDP`	Read / Write	Login-based currency cookie	Base64-encoded string	365 days 7 days (Safari)	`setUserIdentities()`	—
Zcookieid	Third-party	`zc`	Read / Write	Zeotap user identifier set via smart pixel endpoint	Random UUID	730 days	POST calls from SDK GET calls for cookie syncs	—
Capping Cookie	Third-party	`zsc`	Read / Write	Limits frequency of cookie syncs with channel partners (e.g. DoubleClick)	Base64-encoded string	1 day	POST calls from SDK GET calls for cookie syncs	—
User Consent	Third-party	`zuc`	Read / Write	Stores non-TCF consent at account level	Base64-encoded string	365 days	POST calls from SDK GET calls for cookie syncs	—

Third-party cookies are blocked by default in Safari, blocked or isolated per site by default in Firefox, and individual users can block them in any browser. Google announced in July 2024 that it will not deprecate third-party cookies in Chrome, and confirmed in April 2025 that users will continue to manage them through Chrome’s Privacy and Security settings.

The following Zeotap third-party cookies do not operate in browsers or sessions where third-party cookies are blocked:

ZC: Used for ID extension.
ZSC: Limits cookie sync calls per session.
ZUC: Legacy custom consent cookie.

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If you have questions or need assistance, contact Zeotap Support or raise a ticket through the support portal.

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All about cookie syncing

How Zeotap CDP Uses Cookies

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​Cookie Syncing

​How Zeotap CDP Uses Cookies

​Cookie Reference

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Cookie Syncing

How Zeotap CDP Uses Cookies

Cookie Reference

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